1. Field of the Invention
The invention relates to a resin sealing type semiconductor device in which an electronic component and so on are resin-sealed and a method of manufacturing the same. The invention also relates to a resin sealing type electronic device in which an electronic component and so on are resin-sealed.
2. Description of the Related Art
A resin sealing type semiconductor device in which a semiconductor die is sealed in a resin package and a resin sealing type electronic device in which an electronic component and so on are sealed in a resin package have been conventionally known. These resin sealing type semiconductor devices and so on are completed by providing a lead frame, die-bonding various semiconductor dies or electronic components to the lead frame using solder, Ag paste or the like, electrically connecting the semiconductor dies and so on and the lead frame by wire-bonding using an Al wire or an Au wire, resin-sealing these except an outer lead portion, cutting tie bars, and bending leads according to needs. A technique of connecting the outer lead extending from the resin package to an electrode on a PCB substrate by soldering or the like has been also known.
A resin sealing type semiconductor device and a method of manufacturing the same, and a resin sealing type electronic device are described in Japanese Patent Application Publication No. 2005-64076 and “Advanced semiconductor packaging technologies by an illustration book” edited by Semiconductor technologies solutions workshop (the first edition issued on Sep. 25, 2007 by Kogyo Chosakai Publishing Co., Ltd.).
A lead frame used for a resin sealing type semiconductor device or the like is formed by presswork using a Cu member or the like as a base metal. Usually, Ni plating or the like is applied to the surface thereof. Since the presswork is performed by applying high pressure to a metal board made of a Cu member from one side to the other side, small lead burrs are formed on the other side of the lead frame made of the Cu member having viscosity. Ni plating applied to the surface of the lead frame is also applied to these small lead burrs. These lead burrs cause the following problems in a resin sealing type semiconductor device and so on and a process of manufacturing the same, and a resin sealing type electronic device.
In a process of manufacturing a resin sealing type semiconductor device, Sn type alloy plating, Sn type solder plating or the like such as Sn—Cu plating is applied to the surfaces of outer leads in order to obtain the anticorrosiveness and solderability of the surfaces of the outer leads after the resin sealing process is completed, and a process of cutting tie bars and so on are then performed.
In the case of the solder plating, a solder plating layer is formed on all of the outer leads, and the solder is also unstably plated on the small lead burrs formed by the presswork. In the subsequent process of cutting the tie bars, this solder plating layer applied to the small lead burrs peels off to form mustache-like solder burrs, thereby causing a problem of short-circuiting the outer leads and so on.
Furthermore, in a case of using a resin sealing type electronic device by attaching it to an electronic control portion of an automobile, a surface of a bended outer lead may be spot-welded to the side surface of the external electrode of the electronic control portion for a mechanical strength, reliability or the like against the vibration of the automobile. In this case, due to the protruding lead burrs described above, the surface of the outer lead and the surface of the external electrode are not bonded firmly and a welding failure is likely to occur. On the other hand, in a case of bonding an electronic component to an inner lead inside the resin package, since the opposite surface to the lead burr formation surface forms a rounded surface of which the ends are rounded, when an electronic component is bonded to the rounded surface, there occurs a problem that the bonding area is small to cause a connection failure and so on.